Biochemical Mechanisms of Altered Metabolism in Ischemic Heart
Oxygen deficiency in heart muscle is most commonly induced by reduction in coronary flow, referred to as ischemia. As contrasted to hypoxia or anoxia in which flow of blood with low or zero oxygen tension is maintained, ischemia leads to accumulation of metabolic products that further modify rates of biochemical reactions. After periods of severe ischemia ranging from 30 minutes to 1 hour or more, irreversible damage occurs. Damage of this severity is characterized by disruption of the plasma membrane that is preceded by swelling of both the cell and mitochondria. Concurrently, the myofibrils and intercellular junctions are disrupted, and there is margination of nuclear chromatin. Reperfusion of an irreversibly-injured cell leads to accumulation of Ca++ within the mitochondria and failure to recover contractile activity.
KeywordsLysosomal Enzyme Heart Muscle Citric Acid Cycle Autophagic Vacuole Altered Metabolism
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